What is the equation of the vertical asymptote of f(x) = (2x+3)/(x-7)?

A vertical asymptote of a rational function occurs where the denominator is zero and the numerator is not. Set $x - 7 = 0$ to get $x = 7$; the numerator there is $2(7) + 3 = 17$, which is nonzero. So the vertical asymptote is $x = 7$, choice B. Choice A ($x = -7$) has the wrong sign. Choice C ($x = 2$) uses the leading coefficient of the numerator, which relates to the horizontal asymptote $y = 2$, and is not a vertical line anyway. Choice D ($y = 7$) is written as a horizontal line, which is not the form of a vertical asymptote.